Damper sequencer

ABSTRACT

A fluid-flow apparatus having a damper frame provided with walls forming separate side-by-side flow paths for hot, cold and bypass air. Damper elements are pivotally mounted on shafts and arranged in the flow paths for blocking and unblocking same. Each shaft has a pinion gear mounted thereon for pivotal movement with the shaft and associated damper element. Rack gear segments are provided on a longitudinally slidably mounted carrier bar for engaging the pinion gears in a predetermined sequence which places in a blocked position one of the hot and cold air flow paths whenever the other flow path of that pair is simultaneously in an unblocked position. The bypass air flow path is unblocked when either the hot or cold air flow path is only partially unblocked. Spring or cam elements cooperate with flats on the damper element shaft for releasably retaining them in preselected positions.

[ 1 Nov. 12, 1974 1 DAMPER SEQUENCER [76] Inventor: James E. Wells, Rt.3, Box 163-A,

Pensacola, Fla. 32503 [22] Filed: Sept. 14,1972 [21] Appl. No.: 288,984

Finkel 137/601 Primary Examiner-Manuel A. AtItODQ AssistantExaminer-Daniel J. OConnor Attorney, Agent, or FirmClarence A. OBrien;Harvey B. Jacobson ABSTRACT A fluid-flow apparatus having a damper frameprovided with walls forming separate side-by-side flow paths for hot,cold and bypass air. Damper elements are pivotally mounted on shafts andarranged in the flow paths for blocking and unblocking same. Each shafthas a pinion gear mounted thereon for pivotal movement with the shaftand associated damper element. Rack gear segments are provided on alongitudinally slidably mounted carrier bar for engaging the piniongears in a predetermined sequence which places in a blocked position oneof the hot and cold air flow paths whenever the other flow path of thatpair is simultaneously in an unblocked position. The bypass air flowpath is unblock-ed when either the hot or cold air flow path is onlypartially unblocked.

Spring or cam elements cooperate with flats on' the damper element shaftfor releasably retaining them in preselected positions.

9 Claims, 14 Drawing Figures PAIENTEU nuv 12 19m SHIT 1 BF 3 1 DAMPERSEQUENCER BACKGROUND OF THE INVENTION 1. Field of the Invention Thisinvention relates generally to fluid-flow control apparatus and, inparticular, to a damper unit having separate hot, cold, and bypass airflow paths.

2. Description of the Prior Art Air conditioning systems are known whichemploy a damper system having hot and cold air flow paths arrangedside-by-side. When a cold air flow-path damper tioned.

SUMMARY OF THE INVENTION It is an object of the present invention toprovide a hot-cold deck damper system in which only one of the hot deckand cold deck dampers may be simultaneously opened.

It is another object of the present invention to provide a hot-cold deckdamper system having bypass air mixable with either the hot or cold airfor effective tempcrature control.

lt is a further object ofthe present invention to provide a dampersystem which will emit a constant volume of air at all times; the hot,cold, and bypass air flows beingdesigned to have the same staticpressure drop.

It is yet another object of the present invention to provide anefficient damper system which will be simple and reliable in design,easy to install even in relatively inaccessible areas, comparativelymaintenance free, and adaptable to all presently used damper operatingdevices, including electric, electronic, and fluid actuated automatictypes with either push-pull or rotating power strokes.

These and other objects are achieved according to the present inventionby providing a fluid-flow control apparatus having a damper unit withdampers associated with a plurality of fluid flow paths for blocking andunblocking same, and an arrangement for selectively actuating thedampers-in a predetermined sequence placing in a blocked position one ofa pair of the flowpaths whenever the other flow-path of the pair'issimultaneously in anunblocked position.

The pair offlow-pathsreferred to above are preferably the hot and coldair flow-paths.

According to a preferred embodiment of the present invention, thedampers are mounted on pivotally mounted shafts for movement therewith.Pinion gears are also mounted on the shafts for movement there.- with,and are sequentially engaged by rack gear segments mounted on alongitudinally slidably mounted carrier bar which may be actuated in aknown manner by a conventional thermostatic operator. Any desiredsequence of the dampers may be realized by proper arrangement ofthe rackgear segments on the carrier bar.

Spring or cam elements are advantageously provided for cooperating withplanar surfaces, or flats provided on the shafts and releasably retainthe shafts in predetermined positions.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout.

BREIF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary, schematic,vertical, longitudinal sectional view showing a prior art fluid-flowcontrol system.

FIG. 2 is a fragmentary, schematic, vertical, longitudinal sectionalview similar to FIG. 1, but showing a fluid-flow control systemaccording to the present invention.

FIG. 3 is a fragmentary, side elevational view showing a preferredembodiment of a damper system according to the present invention.

FIG. 4 is a fragmentary, end elevational view of the apparatus of FIG.3.

FIGS. 5 to 7 are schematic representations of apparatus according to thepresent invention in bypass and cooling modes.

FIGS. 8 to 10 are schematic representations of appa- I ratus accordingto the present invention in bypass and heating modes.

FIG. 11 is a fragmentary, side elevational view showing a modified shaftindexing arrangement according to the present invention.

FIG. 12 is a fragmentary sectional view takengenerally along the line12-12 of FIG. 11.

FIG. 13 is a fragmentary, side elevational view showing yet anothermodififed shaft indexing arrangement according to the present invention.

FIG. 14 is a fragmentary, sectional view taken generally along the linel414 of FIG. 13.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 of the drawings shows aprior art hot-cold deck unit 10 having a conduit 12 provided with a wall14 forming two side-by-side flow paths. A heating coil l6 and a coolingcoil 18 are arranged in respective flow paths, together with dampers 20and 22. This unit 10 controls-temperature in a space (not shown) to beconditioned by mixing air from each flow path, as discussed above.

Coils 16, 18 may be, for example, fluid coils as are well know, oralternatively, a conventional central station air handling unit (notshown) can condition the air in a known manner and supply it to conduit12. Further, various electrical heating and coolingdevices can.

be arranged in the respective flow paths.

FIG. 2 of the drawings shows a fluid-flow control system 24 according tothe present invention. This system 24 includes fluid passage formingconduit 26 having interior-walls 28 and 30 defining hot, cold, andbypass air flow paths in side-by-side arrangement. A damper unit 31. hasdamper elements 32, 34, and 36 associated with the hot, bypass, and coldflow paths, respectively. The conditioned air may be supplied as set outabove for the prior art embodiment shown in FIG. 1.

System 24 also includes an arrangement to be set out below forselectively moving damper elements 32, 34 and'36 ina predeterminedsequence which places in a blocked position one of the hot and cold flowpaths whenever the other flow path of the pair is simultaneously in anunblocked position.

Referring now to FIGS. 3 and 4 of the drawings, damper unit 31 has aframe 37 of conventional con struction and connected to conduit 26 asby, for example, flanges and'known fasteners (not shown). Walls 38, 39cooperate with walls 28, 30 to define the flow path through unit 31.Shafts 40, 42 and 44 are pivotally mounted in a conventional manner toouter walls of frame 37 and damper elements 32, 34, and 36 are mountedon the shafts 40, 42, and 44, respectively, in a conventional manner formovement therewith. The outer walls of frame 37 may be formed in asuitable, known manner as from, for example, a sheet metal. Pinion gears46, 48 and 50 are also mounted on respective shafts 40, 42 and 44 formovement therewith. Associated with these pinion gears 46, 48 and 50 arerack gear segments 52, 54, and 56, respectively, fixedly mounted on alongitudinal carrier bar 58 arranged in bracket'60 for longitudinalsliding movement with respect to frame 37. Only one of segments 52 and56 engage their associated pinion gears 46 and 50 at a time.

' Leaf springs 62, 64, and 66 are cantilever mounted on frame 37 in asuitable, known manner, and are arranged for cooperating with shafts 40,42 and 44, respectively, for indexing the shafts and their associateddamper elements by sequentially engaging planar surfaces 67 provided onat least a portion of the shafts and r'eleasably retaining same in oneof a plurality of predetermined positions corresponding to desireddamper element positions. As illustrated, shafts 40, 42, and 44 areround in cross-section with a square portion at the one end extendingbeyond frame 37'adjacent the pinion gears and rack segments.

FIGS. to 7 show schematically the positions and relationships of damperelements'32, 34, and 36 for, re-

- spectiv ely, 100 percent bypass air, 50 percent cool air and 50percent bypass air, and W0 percent cool air being passed through unitSLFIGS. 8 to show the comparable positions and relationships for bypassand heating modes.

FIGS. 11 and 12 of the drawings show a modified shaft indexingarrangement. A, for example, U-shaped spring 68 is mounted on an outerwall of frame 37 as by clips 70, 72 retained by, for example, screwfasteners. The legs 73 of spring 68 will simultaneously engage opposedplanar surfaces 67 of the associated shaft for insuring positiveindexing of thatshaft. 7 Yet another modified shaft indexing arrangementis shown in FIGS. 13 and 14 of the drawings. Here, a rack gear segment74, which may be substituted for any of the segments 52, 54 and 56, isprovided with a cam portion 76 for engaging surfaces 67 of the shaftsand holding a damper element in a closed or flow path blocking position.The rack gear teeth will tend to hold the damper elements in an open orflow path unblocking position, since cam portion 76 will only releasablyengage surfaces 67 when the associated damper element is in a flow pathblocking position.

A damper unit 31 according to the present invention simply andefficiently controls fluid flow by passing hot,

cold, and bypass air along their associated flow paths,

and blocking and unblocking the hot and cold air flow paths whenever theother flow path of this pair is simultaneously in the opposite mode sothat the hot and cold air flow paths are never simultaneously unblocked.However, the bypass air flow path may be unblocked when either of theflow paths is only partially unblocked, as shown in FIGS. 6 and 9. Byproviding each flow path with the same pressure drop, a constant airflow into the space (not shown) to be conditioned is accordinglyassured. This is due to the constant flow path area presented by thedifferent damper element positions as is illustrated in FIGS. 5 to 10 ofthe drawings. That is, either only one of the damper elements is in afully open position with the other two in closed or blocked positions,or two of the damper elements are in, for example, half open positionsresulting in the same volume of air being passed thereby as if onedamper element was fully open and the other two damper elements closed.

A damper unit 10 according to the present invention will operate atincreased efficiency compared to known damping devices, and will reduceenergy expenditures and cost, thereby saving the operator expense andalleviating power shortages.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly all suitable modifications andequivalents maybe resorted to, falling within the scope of the invention.

What is claimed as new is as follows: 1. A'fluid-flow apparatus,comprising, in combination:

a. damper means associated with three fluid-flow paths for movingbetween a position blocking each flow path and a position unblockingsame, two of I the paths normally blocked and one of the paths normallyunblocked, the damper means including a frame provided with wallportions forming the flow paths, damper elements arranged in the flowpaths, and shafts pivotally mounted to the frame,

said damper elements mounted on the shafts for pivotal movementtherewith, b. means for selectively moving the damper elements in apredetermined sequence retaining in a blocked position one of the twonormally blocked flow paths whenever the other flow path of the pair isin unblocked position, the moving means including pinion gears mountedon said shafts for movement therewith, rack gear segments associatedwith said on the gear segments and arranged for engaging the planarsurfaces.

5. A structure as defined in claim, 1, wherein the three fluid flowpaths are one each for hot, cold, and

bypass air, and the two normally blocked flow paths are those for hotand cold air.

6. A structure as defined in claim 5, further including fluid passagemeans including a conduit having walls defining the flow paths inside-by-side arrangement.

7. A structure as defined in claim 6, wherein each of said shafts isprovided with a plurality of planar surfaces, and the retaining means issprings mounted on said frame and arranged for engaging the planarsurfaces.

8. A structure as defined in claim 6, wherein each of said shaftsisprovided with a plurality of planar surfaces, and the retaining meansis cam portions provided on thegear segments and arranged for engagingthe planar surfaces. 1

9. A structure as defined in claim 1, further including fluid passagemeans including a conduit having walls defining the flow paths inside-by-side arrangement.

1. A fluid-flow apparatus, comprising, in combination: a. damper meansassociated with three fluid-flow paths for moving between a positionblocking each flow path and a position unblocking same, two of the pathsnormally blocked and one of the paths normally unblocked, the dampermeans including a frame provided with wall portions forming the flowpaths, damper elements arranged in the flow paths, and shafts pivotallymounted to the frame, said damper elements mounted on the shafts forpivotal movement therewith, b. means for selectively moving the damperelements in a predetermined sequence retaining in a blocked position oneof the two normally blocked flow paths whenever the other flow path ofthe pair is in unblocked position, the moving means including piniongears mounted on said shafts for movement therewith, rack gear segmentsassociated with said pinion gears, and a longitudinal carrier barmounted on said frame for longitudinal movement with respect thereto,said gear segments mounted on said carrier bar for movement therewith,and a pair of the gear segments arranged for always movably engaging thepinion gear associated with the normally unblocked one of the flow pathsand sequentially engaging only one of the other, normally blocked flowpaths for obtaining a constant flow from the three paths, the damperelement of the flow path associated with the disengaged pinion gearbeing arranged in a position blocking the flow path associatedtherewith.
 2. A structure as defined in claim 1, further including meansfor releasably retaining said shafts in one of a plurality ofpredetermined positions.
 3. A structure as define in claim 2, whereineach of said shafts is provided with a plurality of planar surfaces, andthe retaining means is springs mounted on said frame and arranged forengaging the planar surfaces.
 4. A structure as defined in claim 2,wherein each of said shafts is provided with a plurality of planarsurfaces, and the retaining means is cam portions provided on the gearsegments and arranged for engaging the planar surfaces.
 5. A structureas defined in claim 1, wherein the three fluid flow paths are one eachfor hot, cold, and bypass air, and the two normally blocked flow pathsare those for hot and cold air.
 6. A structure as defined in claim 5,further including fluid passage means including a conduit having wallsdefining the flow paths in side-by-side arrangement.
 7. A structure asdefined in claim 6, wherein each of said shafts is provided with aplurality of planar surfaces, and the retaining means is springs mountedon said frame and arranged for engaging the planar surfaces.
 8. Astructure as defined in claim 6, wherein each of said shafts is providedwith a plurality of planar surfaces, and the retaining means is camportions provided on the gear segments and arranged for engaging theplanar surfaces.
 9. A structure as defined in claim 1, further includingfluid passage means including a conduit having walls defining the flowpaths in side-by-side arrangement.